Impact of synbiotic supplementation on cardiometabolic and anthropometric indices in patients with metabolic syndrome: A systematic review and meta-analysis of randomized controlled trials

The effect of microbiome-modulating therapeutics on glucose homeostasis in metabolic syndrome: A systematic review, meta-analysis, and meta-regression of clinical trials

BACKGROUND

Metabolic syndrome (MetS) is a chronic disorder featuring overweight/obesity, high blood pressure, and dysfunction of lipid and carbohydrate metabolism. Microbiome-modulating probiotics, prebiotics, synbiotics and fecal microbiota transplant (FMT) are promising adjunct therapies for improving parameters of glucose homeostasis and insulinemia.

METHODS

We conducted a comprehensive systematic review, meta-analyses, and meta-regressions to investigate the effect of the abovementioned microbiome therapies on various biomarkers after screening clinical trials published through April 2023. We pooled data using random effects meta-analyses, reporting them as mean differences (MDs) with 95 % confidence intervals (CIs), and conducting univariate linear model meta-regressions.

RESULTS

Data from 21 trial comparisons across 19 studies (n = 911) revealed that, compared to placebo/control, microbiome-modulating therapies were associated with statistically significant changes in fasting plasma glucose (MD: 4.03 mg/dL [95%CI: 6.93; -1.13]; p effect = 0.006, I2 = 89.8 %), and fasting insulin (MD: 2.56 μU/mL [95%CI: 4.28; -0.84]; p effect = 0.004, I2 = 87.9 %), but not insulin resistance or sensitivity indices and HbA1c. Age, baseline BMI, baseline biomarker value, pro/synbiotic dosage, trial duration, nutraceutical type, and WHO region were factors affecting the efficacy of these interventions at producing changes in biomarkers, signaling the potential role of personalized precision medicine adjunct therapy for deranged glucose homeostasis in patients with MetS. Nevertheless, presence of heterogeneity calls for further investigation before their clinical application.

CONCLUSIONS

Probiotics, prebiotics, synbiotics and FMT supplementation improved fasting glucose and insulin in patients with MetS. Further large-scale and high-quality trials are required before potential clinical applications.

Is There Evidence to Support Probiotic Use for Healthy People?

Probiotics are typically marketed as foods and dietary supplements, categories for products intended to maintain health in generally healthy populations and which, unlike drugs, cannot claim to treat or cure disease. This review addresses the existing evidence that probiotics are beneficial to healthy people. Our approach was to perform a descriptive review of efficacy evidence that probiotics can prevent urinary, vaginal, gastrointestinal, and respiratory infections, and improve risk factors associated with cardiovascular health or reduce antibiotic use. Other endpoints such as mental, dental, or immune health were not specifically addressed. We concluded that there is sufficient evidence of efficacy and safety for clinicians and consumers to consider using specific probiotics for some indications - such as the use of probiotics to support gut function during antibiotic use or to reduce the risk of respiratory tract infections - for certain people. However, we did not find a sufficiently high level of evidence to support unconditional, population-wide recommendations for other preventive endpoints we reviewed for healthy people. Although evidence for some indications is suggestive of the preventive benefits of probiotics, additional research is needed.

Appetite sensation improvement by synbiotic supplementation in patients with metabolic syndrome: A randomized controlled clinical trial

The potential link between dysbiosis, features of metabolic syndrome (MetS), inflammation, and sensation impairment has been recently recognized. However, in this context, there are few indications available regarding the effects of co-supplementation with Bacillus indicus, Bacillus coagulans, and fructooligosaccharide (FOS) prebiotics on patients with MetS. Therefore, this study aimed to investigate the effects of synbiotic supplementation on glycemic indices, inflammatory biomarkers, and appetite among adults with MetS. This study is a randomized, double-blind, placebo-controlled clinical trial conducted in the Endocrine and Metabolism Research Center outpatient clinic in Isfahan, Iran. Fifty-eight MetS patients were randomly assigned to receive either synbiotics (n = 29) or placebo (n = 29) supplementation twice per day for 8 weeks. Finally, 55 patients were recruited for analyses (28 in the intervention group and 27 in the placebo group). Random permuted blocks and a computer-generated random number table were used for treatment allocation. No adverse effects were reported during the study. There were no significant differences in glycemic indices and inflammatory markers within- and between groups (all p > .05). However, a significant increase in the sensation of fullness was documented in the synbiotic group. In conclusion, the eight-week treatment did not improve glycemic control and inflammatory markers. Nevertheless, it demonstrated potential efficacy in enhancing participants' appetite sensations, warranting further evaluation in longer intervention periods during future clinical trials.

Effects of probiotics, prebiotics and synbiotics on anthropometric, cardiometabolic and inflammatory markers: An umbrella review of meta-analyses

BACKGROUND & AIMS

Though probiotics, prebiotics and synbiotics have been shown to confer health benefits, their effects on cardiometabolic risk factors remain unclear. Therefore, we conducted an umbrella review to examine their effectiveness on anthropometric, cardiometabolic and inflammatory markers.

METHODS

We conducted an umbrella review on eligible systematic reviews with meta-analysis (SRMA) published from journals' inception till 13 January 2023 retrieved from seven electronic databases (CINAHL, EMBASE, ProQuest, PubMed, Scopus, The Cochrane Library, and Web of Science). Methodological quality was appraised using the Assessment of Multiple Systematic Reviews 2 (AMSTAR2) tool and certainty of evidence was graded into five classes. Random-effects meta-analyses were performed on outcome effect sizes at the SRMA and primary study levels. Extent of overlapping articles were evaluated using corrected cover area.

RESULTS

24 systematic reviews representing 265 unique studies, 1076 unique effect sizes and 25,973 subjects were included. Synbiotics were evidently more effective in improving weight (-1.91 kg, 95%CI -3.45 kg to -0.37 kg, p = 0.02), total cholesterol (-12.17 mg/dl, 95%CI -17.89 mg/dl to -6.46 mg/dl, p < 0.001), low-density lipoprotein (-12.26 mg/dl, 95%CI -18.27 mg/dl to -6.25 mg/dl, p < 0.01), waist circumference (-1.85 cm, 95%CI -2.77 cm to -0.94 cm, p < 0.01), and fasting plasma glucose (-9.68 mg/dl, 95%CI -16.18 mg/dl to -3.18 mg/dl, p < 0.01). Prebiotics were more effective in improving body mass index (-0.34 kg/m2, 95%CI -0.48 kg/m2 to -0.20 kg/m2, p < 0.01), and HOMA-IR (-0.92, 95%CI -1.91 to 0.07, p = 0.06). Probiotics were shown to be more effective in reducing diastolic blood pressure (-1.34 mmHg, 95%CI -2.14 mmHg to -0.55 mmHg, P < 0.01) improving insulin level change (-0.84 mIU/mL, 95%CI -1.27 mIU/mL to -0.41 mIU/mL, p < 0.01), and the percentage of body fat (-0.66%, 95%CI -0.70% to -0.61%, p < 0.01). For all outcomes, the credibility of evidence was classified as class IV.

CONCLUSION

Pre-, pro-, and synbiotics can significantly enhance anthropometric indices, glucose and lipid profiles, blood pressure, and inflammatory markers in individuals confronting obesity. While suggesting their supplementation holds promise for this population, the true clinical impact hinges on tailoring these interventions to specific indications and customizing treatment strategies to align with individual patient needs.

The effects of prebiotic, probiotic or synbiotic supplementation on overweight/obesity indicators: an umbrella review of the trials' meta-analyses

Background

There is controversial data on the effects of prebiotic, probiotic, or synbiotic supplementations on overweight/obesity indicators. Thus, we aimed to clarify this role of biotics through an umbrella review of the trials' meta-analyses.

Methods

All meta-analyses of the clinical trials conducted on the impact of biotics on overweight/obesity indicators in general populations, pregnant women, and infants published until June 2023 in PubMed, Web of Sciences, Scopus, Embase, and Cochrane Library web databases included. The meta-analysis of observational and systematic review studies without meta-analysis were excluded. We reported the results by implementing the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) flowchart. The Assessment of Multiple Systematic Reviews-2 (AMSTAR2) and Grading of Recommendations Assessment, Development, and Evaluation (GRADE) systems were used to assess the methodological quality and quality of evidence.

Results

Overall, 97 meta-analysis studies were included. Most studies were conducted on the effect of probiotics in both genders. Consumption of prebiotic: 8-66 g/day, probiotic: 104 -1.35×1015 colony-forming unit (CFU)/day, and synbiotic: 106-1.5×1011 CFU/day and 0.5-300 g/day for 2 to 104 weeks showed a favorable effect on the overweight/obesity indicators. Moreover, an inverse association was observed between biotics consumption and overweight/obesity risk in adults in most of the studies. Biotics did not show any beneficial effect on weight and body mass index (BMI) in pregnant women by 6.6×105-1010 CFU/day of probiotics during 1-25 weeks and 1×109-112.5×109 CFU/capsule of synbiotics during 4-8 weeks. The effect of biotics on weight and BMI in infants is predominantly non-significant. Prebiotics and probiotics used in infancy were from 0.15 to 0.8 g/dL and 2×106-6×109 CFU/day for 2-24 weeks, respectively.

Conclusion

It seems biotics consumption can result in favorable impacts on some anthropometric indices of overweight/obesity (body weight, BMI, waist circumference) in the general population, without any significant effects on birth weight or weight gain during pregnancy and infancy. So, it is recommended to intake the biotics as complementary medications for reducing anthropometric indices of overweight/obese adults. However, more well-designed trials are needed to elucidate the anti-obesity effects of specific strains of probiotics.

Targeting the Gut Microbiome to Treat Cardiometabolic Disease

PURPOSE OF REVIEW

Cardiometabolic diseases, which include obesity, type 2 diabetes, and cardiovascular diseases, constitute a worldwide health crisis of unparalleled proportions. The human gut microbiota has emerged as a prominent topic of inquiry in the search for novel treatment techniques. This review summarizes current research on the potential of addressing the gut microbiota to treat cardiometabolic disease.

RECENT FINDINGS

Recent studies have highlighted a complex link between the gut microbiota and host physiology, shedding light on the several processes through which gut microorganisms impact metabolic health, inflammation, and cardiovascular function. Furthermore, a growing corpus of research is available on microbiome-based therapies such as dietary interventions, probiotics, prebiotics, synbiotics, and fecal microbiota transplantation. These therapies show promise as methods for reshaping the gut microbiota and, as a result, improving cardiometabolic outcomes. However, hurdles remain, ranging from the intricacies of microbiome research to the necessity for tailored treatments that take individual microbial variations into consideration, emphasizing the significance of furthering research to bridge the gap between microbiome science and clinical practice. The gut microbiome is a beacon of hope for improving the management of cardiometabolic disease in the age of precision medicine, since its association with their pathophysiology is constantly being unraveled and strengthened. Available studies point to the potential of gut microbiome-based therapeutics, which remains to be tested in appropriately designed clinical trials. Further preclinical research is, however, essential to provide answers to the existing obstacles, with the ultimate goal of enhancing patient care.

Maternal breastfeeding is associated with offspring microbiome diversity; a secondary analysis of the MicrobeMom randomized control trial

Background

Microbial dysbiosis in infancy can influence long-term health outcomes such as childhood obesity. The aim of this study is to explore relationships among maternal well-being during pregnancy, breastfeeding, and the infant gut microbiome.

Methods

This is a secondary analysis of healthy pregnant women from the MicrobeMom study, a double-blind randomized control trial of maternal probiotic supplementation (Bifidobacterium breve 702258) versus placebo antenatally and up to 3 months postpartum. Maternal well-being was assessed using the WHO-5 well-being index at 16 weeks' and 34 weeks' gestation. Breastfeeding practices were recorded at discharge from hospital and at 1 month postpartum. Infant stool samples were obtained at 1 month of age. Next generation shotgun sequencing determined infant microbial diversity. Independent sample t-tests and Mann-Whitney U tests informed adjusted regression analysis, which was adjusted for delivery mode, antibiotics during delivery, maternal age and body mass index (BMI), and probiotic vs. control study group.

Results

Women (n = 118) with at least one measure of well-being were on average 33 years (SD 3.93) of age and 25.09 kg/m2 (SD 3.28) BMI. Exclusive breastfeeding was initiated by 65% (n = 74). Any breastfeeding was continued by 69% (n = 81) after 1 month. In early and late pregnancy, 87% (n = 97/111) and 94% (n = 107/114) had high well-being scores. Well-being was not associated with infant microbial diversity at 1 month. In adjusted analysis, exclusive breastfeeding at discharge from hospital was associated with infant microbial beta diversity (PC2; 0.254, 95% CI 0.006, 0.038). At 1 month postpartum, any breastfeeding was associated with infant microbial alpha diversity (Shannon index; -0.241, 95% CI -0.498, -0.060) and observed species; (-0.325, 95% CI -0.307, -0.060), and infant microbial beta diversity (PC2; 0.319, 95% CI 0.013, 0.045). Exclusive breastfeeding at 1 month postpartum was associated with infant alpha diversity (Shannon index -0.364, 95% CI -0.573, -0.194; Simpson index 0.339, 95% CI 0.027, 0.091), and infant's number of observed microbial species (-0.271, 95% CI -0.172, -0.037).

Conclusion

Breastfeeding practices at 1 month postpartum were associated with lower microbial diversity and observed species in infants at 1 month postpartum, which is potentially beneficial to allow greater abundance of Bifidobacterium.

Clinical trial registration

ISRCTN53023014.

The Effects of Probiotics on Cholesterol Levels in Patients With Metabolic Syndrome: A Systematic Review

The prevalence of metabolic syndrome has been increasing over the past few years, especially in the United States. As a result, it increases the risk of heart disease, stroke, and diabetes mellitus, thus causing significant health issues. Probiotics have been studied to have effects on maintaining blood cholesterol levels by altering the gut microbiota. This systematic review aims to find the effects that probiotics would have on lipid levels when given to patients with metabolic syndrome. In total, articles collected from PubMed, Google Scholar, and ScienceDirect were analysed. The results of the majority of the studies revealed that probiotics have some significant effects on cholesterol levels. It has shown a reduction in triglycerides and lower-density lipoprotein (LDL), thereby decreasing cholesterol levels in the blood. However, further investigations must be carried out so in order to create a more detailed and specific explanation of the effects and mechanisms of probiotics on maintaining cholesterol levels in the blood.

Effects of synbiotics supplementation on anthropometric and lipid profile parameters: Finding from an umbrella meta-analysis

Introduction

Several systematic reviews and meta-analyses have been carried out to assess the impact of synbiotics on lipid profiles and anthropometric parameters. In this regard, an umbrella meta-analysis was performed to provide a more accurate view of the overall impacts of synbiotic supplementation on lipid profile and anthropometric parameters.

Methods

Databases such as PubMed, Scopus, Embase, Web of Science, and Google Scholar were searched for this study from inception to January 2022. A random-effects model was applied to evaluate the effects of synbiotic supplementation on lipid profile and anthropometric parameters. The methodological quality of eligible articles was evaluated using the AMSTAR2 questionnaire. The GRADE approach was used to evaluate the overall certainty of the evidence in the meta-analyses.

Results

Meta-analyses of 17 studies revealed significant decreases in body mass index (BMI) (ES: -0.13 kg/m2; 95% CI: -0.19, -0.06, p < 0.001, I2 = 0.0%, p = 0.870), BW (ES: -1.30 kg; 95% CI: -2.19, -0.41, p = 0.004, I2 = 88.9%, p < 0.001), waist circumference (WC) (ES: -1.80 cm; 95% CI: -3.26, -0.34, p = 0.016, I2 = 94.1%, p < 0.001), low-density lipoprotein cholesterol (LDL-C) (ES: -2.81 mg/dl; 95% CI: -3.90, -1.72, p < 0.001, I2 = 95.1%, p < 0.001), total cholesterol (TC) (ES = -2.24 mg/dl; 95% CI: -3.18, -1.30, p < 0.001, I2 = 94.5%, p < 0.001), and triglyceride (TG) (ES: -0.43 mg/dl; 95% CI: -0.79, -0.07, p = 0.019, I2 = 78.0%, p < 0.001) but not high-density lipoprotein cholesterol (HDL-C) (ES: 0.23 mg/dl; 95% CI: -0.11, 0.56, p = 0.193, I2 = 45.2%, p = 0.051) following synbiotic supplementation.

Discussion

The present umbrella meta-analysis suggests synbiotic supplementation can slightly improve lipid profile and anthropometric indices and might be a therapeutic option for obesity and its related disorders.

Systematic review registration

www.crd.york.ac.uk/prospero, identifier CRD42022304376.

Gut Microbiota and Coronary Artery Disease: Current Therapeutic Perspectives

The human gut microbiota is the community of microorganisms living in the human gut. This microbial ecosystem contains bacteria beneficial to their host and plays important roles in human physiology, participating in energy harvest from indigestible fiber, vitamin synthesis, and regulation of the immune system, among others. Accumulating evidence suggests a possible link between compositional and metabolic aberrations of the gut microbiota and coronary artery disease in humans. Manipulating the gut microbiota through targeted interventions is an emerging field of science, aiming at reducing the risk of disease. Among the interventions with the most promising results are probiotics, prebiotics, synbiotics, and trimethylamine N-oxide (TMAO) inhibitors. Contemporary studies of probiotics have shown an improvement of inflammation and endothelial cell function, paired with attenuated extracellular matrix remodeling and TMAO production. Lactobacilli, Bifidobacteria, and Bacteroides are some of the most well studied probiotics in experimental and clinical settings. Prebiotics may also decrease inflammation and lead to reductions in blood pressure, body weight, and hyperlipidemia. Synbiotics have been associated with an improvement in glucose homeostasis and lipid abnormalities. On the contrary, no evidence yet exists on the possible benefits of postbiotic use, while the use of antibiotics is not warranted, due to potentially deleterious effects. TMAO inhibitors such as 3,3-dimethyl-1-butanol, iodomethylcholine, and fluoromethylcholine, despite still being investigated experimentally, appear to possess anti-inflammatory, antioxidant, and anti-fibrotic properties. Finally, fecal transplantation carries conflicting evidence, mandating the need for further research. In the present review we summarize the links between the gut microbiota and coronary artery disease and elaborate on the varied therapeutic measures that are being explored in this context.

Bioactive compounds in childhood obesity and associated metabolic complications: Current evidence, controversies and perspectives

Obesity represents the most frequent chronic disease among children worldwide, with a significant global burden on society. Metabolically unhealthy obesity (MUO) can affect children since their first years of life, and novel therapeutic strategies to tackle metabolic complications are under investigation. This review focuses on bioactive compounds and their possible beneficial effects on obesity, particularly omega-3, docosahexaenoic acid, vitamin D, biotics, polysaccharide macromolecules, polyphenols, inositols, alpha lipoic acid, and bromelaine. Our aim is to summarize current evidence about bioactive compounds in the treatment of obesity, highlighting recent findings on their use in children and adolescents. Most studied molecules are omega-3 and vitamin D, despite the heterogeneity between the studies. Moreover, given the emerging interest in the gut-brain axis in the link between metabolic health and microbiota, various studies on prebiotics, probiotics, synbiotics, postbiotics and polysaccharide macromolecules have been considered. Some preclinical studies seem to highlight a possible role of the polyphenols, even if their clinical evidence is still discussed. Lastly, we describe possible effects of inositols and alpha-lipoic acid. Despite some dietary supplements seem to be promising in overweight subjects, only in a few of them a dose/response efficacy has been found in the pediatric age. Innovative, well-designed and targeted clinical trials are then needed to prove the beneficial effects of these compounds that could support the standard behavioral therapy for obesity.

Protection by -Biotics against Hypertension Programmed by Maternal High Fructose Diet: Rectification of Dysregulated Expression of Short-Chain Fatty Acid Receptors in the Hypothalamic Paraventricular Nucleus of Adult Offspring

The role of short-chain fatty acids (SCFAs) in the brain on the developmental programming of hypertension is poorly understood. The present study explored dysregulated tissue levels of SCFAs and expression of SCFA-sensing receptors in the hypothalamic paraventricular nucleus (PVN), a key forebrain region engaged in neural regulation of blood pressure of offspring to maternal high fructose diet (HFD) exposure. We further investigated the engagement of SCFA-sensing receptors in PVN in the beneficial effects of -biotics (prebiotic, probiotic, synbiotic, and postbiotic) on programmed hypertension. Maternal HFD during gestation and lactation significantly reduced circulating butyrate, along with decreased tissue level of butyrate and increased expression of SCFA-sensing receptors, GPR41 and olfr78, and tissue oxidative stress and neuroinflammation in PVN of HFD offspring that were rectified by oral supplement with -biotics. Gene silencing of GPR41 or olfr78 mRNA in PVN also protected adult HFD offspring from programmed hypertension and alleviated the induced oxidative stress and inflammation in PVN. In addition, oral supplement with postbiotic butyrate restored tissue butyrate levels, rectified expressions of GPR41 and olfr78 in PVN, and protected against programmed hypertension in adult HFD offspring. These data suggest that alterations in tissue butyrate level, expression of GPR41 and olfr78, and activation of SCFA-sensing receptor-dependent tissue oxidative stress and neuroinflammation in PVN could be novel mechanisms that underlie hypertension programmed by maternal HFD exposure in adult offspring. Furthermore, oral -biotics supplementation may exert beneficial effects on hypertension of developmental origin by targeting dysfunctional SCFA-sensing receptors in PVN to exert antioxidant and anti-inflammatory actions in the brain.

Role of probiotics/synbiotic supplementation in glycemic control: A critical umbrella review of meta-analyses of randomized controlled trials

The evidence regarding the beneficial effects of probiotics/synbiotic supplementation have been revealed by several meta-analyses, however some of these studies have fielded inconsistent results and a conclusion has yet to be reached. Therefore, the aim of present umbrella meta-analyses was to assess relevant evidence and elucidate the efficacy of probiotics/synbiotic supplementation in glycemic control. A comprehensive search in four databases (Cochrane library, PubMed, Web of science and Scopus) was performed to collect relevant studies up to August 2022, the pooled effects were measured with the use of random/fix-effect model depends on the heterogeneity. A total of 47 eligible meta-analyses involving 47,720 participants were identified to evaluate the pooled effects. The overall results showed that probiotics/synbiotic supplementation delivered significant decreases in fast plasma glucose (ES = -0.408, 95% CI: -0.518, -0.298; P < 0.001; I2 = 82.996, P < 0.001), fast plasma insulin (ES = -1.165, 95% CI: -1.454, -0.876; P < 0.001; I2 = 89.629, P < 0.001), homeostasis model assessment of insulin resistance (ES = -0.539, 95% CI: -0.624, -0.454; P < 0.001; I2 = 56.716, P < 0.001), and glycosylated hemoglobin (ES = -0.186, 95% CI: -0.270, -0.102; P < 0.001; I2 = 59.647, P = 0.001). Subgroup analysis showed that patients with impaired glucose homeostasis might benefit the most from probiotics/synbiotic supplementation. In conclusion, current umbrella meta-analysis strongly supporting the beneficial health effects of probiotics/synbiotic supplementation in glycemic control.

The effect of probiotic and synbiotic consumption on the most prevalent chemotherapy-related complications: A systematic review of current literature

BACKGROUND

To date, many investigations have employed pro-/synbiotic to examine their effects on chemotherapy-related side effects; nevertheless, their findings are inconclusive. To address this issue, we carried out a systematic review to explore the effect of pro-/synbiotic consumption on chemotherapy-related side effects, including nausea, vomiting, mucositis, diarrhea, and constipation in adults using randomized controlled trials (RCTs).

METHODS

The electronic databases, including PubMed, Scopus, and ISI Web of Sciences, were searched systematically from the earliest available date to March 2021 to identify eligible studies. The quality of the enrolled studies was done based on the Cochrane Collaboration Risk of Bias tool.

RESULTS

A total of 10 studies involving 788 individuals were included in the current systematic review with a sample size ranging from 25 to 200, and the mean age ranged from 51.04 to 66.91 years. The findings of this study imply that probiotics consumption may be more effective in terms of mucositis compared to other complications.

CONCLUSION

Further good-quality RCTs with better methodology are called to determine whether and how pro-/synbiotics can prevent or treat chemotherapy-induced side effects. The current systematic review findings may help investigators for future studies regarding the selection study population and probiotic strains.

Effects of probiotic supplementation on major cardiovascular-related parameters in patients with type-2 diabetes mellitus: a secondary-data analysis of a randomized double-blind controlled trial

BACKGROUND

Patients with type-2 diabetes mellitus (T2DM), have a higher risk of future cardiovascular diseases (CVD). Meanwhile, probiotics are shown to positively impact CVD-related parameters. This randomized controlled trial sought to evaluate the effects of probiotic supplementation on fundamental CVD-related parameters including atherogenic index of plasma (AIPs), blood pressure, the Framingham risk score, and antioxidant markers in patients with T2DM.

METHODS

Eligible participants were randomly assigned to receive 2 capsules/day of probiotics [each containing 500 mg of L.acidophilus(5 × 10¹⁰ CFU/g), L.plantarum(1.5 × 10¹⁰ CFU/g), L.fermentum(7 × 10⁹ CFU/g), L.Gasseri(2 × 10¹⁰ CFU/g) and 38.5 mg of fructo-oligo-saccharides], or placebo for 6 weeks. Systolic and diastolic blood pressures (SBP and DBP, respectively), mean arterial blood pressure (MAP), atherogenic indices (the ratios of TC/HDL-C, LDL-C/HDL-C, and logTG/HDL-C), the 10-year Framingham CVD risk score, as well as total anti-oxidant capacity (TAC), paraoxonase (PON) and total oxidant status (TOS) were evaluated before and after the study. Final analyses were adjusted based on baseline parameters, and potential covariates including age, sex, PUFA and sodium intakes.

RESULTS

Sixty participants completed the study. Compared with placebo, probiotic supplementation resulted in a significant decrease in SBP[-9.24 mmHg(- 14.5, - 3.9)], DBP[- 3.71 mmHg(- 6.59, - 0.83)], MAP[- 5.55 mmHg(- 8.8, - 2.31)], the Framingham risk categories [medium-low(1.5) vs. 2 (medium)] and logTG/HDL-C ratio [- 0.08 (- 0.14, 0)] (All P < 0.05) at the end of the study. No significant changes were observed in the antioxidant markers.

CONCLUSION

Overall, probiotic supplementation for 6 weeks led to a significant improvement in major CVD-related parameters in populations with T2DM, suggesting the possible beneficial role of probiotics in lowering the risk of future CVDs associated with diabetes. Nevertheless, more studies are needed to confirm the veracity of these results.

TRIAL REGISTRATION

IRCT2013100714925N1 (registered on November, 9th, 2013).

Impact of walnut consumption on cardio metabolic and anthropometric parameters in metabolic syndrome patients: GRADE-assessed systematic review and dose-response meta-analysis of data from randomized controlled trials

BACKGROUND

In recent years, the effect of walnut consumption on various components of metabolic syndrome (Mets) in different populations has been investigated. However, the findings on the alterations of cardiometabolic and anthropometric indices following walnut consumption in adults with Mets have not been fully conclusive.

METHODS

The current study of eight randomized controlled trials (RCTs) examined the effects of walnut consumption on glucose homeostasis factors (fasting plasma glucose (FPG), insulin, hemoglobin A1C (HbA1c)), lipid profile (triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-c), and high-density lipoprotein cholesterol (HDL-c)), high sensitivity C-reactive protein (hs-CRP) concentrations and anthropometric indices (body weight (BW), body mass index (BMI), and waist circumference (WC)) in trials of 549 participants. A systematic search was conducted in online databases including MEDLINE, Scopus, and Clarivate Analytics Web of Science uses related keywords to detect eligible studies until December 2021. To calculate the weighted mean difference (WMD) and 95% confidence intervals (CIs), a random-effects model was used.

RESULTS

Results from the pooled analysis showed that serum TG concentration was significantly reduced (WMD, - 0.1 mmol/L; 95%CI (- 0.3 to - 0.02); p = 0.02; I2 = 38.6%; p = 0.10), although other lipid profile components (TC, LDL-c, and HDL-c), glucose homeostasis markers (FPG, insulin, and HbA1c), hs-CRP levels, anthropometric indices (BW, BMI, and WC) and blood pressure (SBP and DBP) were not influenced by walnut consumption. A significant dose-response association was detected between the dose of walnut intake and serum concentrations of FPG (Pnon-linearity < 0.03, Pdose-response < 0.001) and HDL-c (Pnon-linearity = 0.01, Pdose-response = 0.006).

CONCLUSIONS

Walnut consumption reduces serum TG levels in individuals with metabolic syndrome, but it cannot affect other cardiometabolic indices. Future well-designed and large RCTs are required to clarify further beneficial effects of walnut consumption on the cardiometabolic profile.

Supplementation with the Symbiotic Formulation Prodefen® Increases Neuronal Nitric Oxide Synthase and Decreases Oxidative Stress in Superior Mesenteric Artery from Spontaneously Hypertensive Rats

In recent years, gut dysbiosis has been related to some peripheral vascular alterations linked to hypertension. In this work, we explore whether gut dysbiosis is related to vascular innervation dysfunction and altered nitric oxide (NO) production in the superior mesenteric artery, one of the main vascular beds involved in peripheral vascular resistance. For this purpose, we used spontaneously hypertensive rats, either treated or not with the commercial synbiotic formulation Prodefen^® (10⁸ colony forming units/day, 4 weeks). Prodefen^® diminished systolic blood pressure and serum endotoxin, as well as the vasoconstriction elicited by electrical field stimulation (EFS), and enhanced acetic and butyric acid in fecal samples, and the vasodilation induced by the exogenous NO donor DEA-NO. Unspecific nitric oxide synthase (NOS) inhibitor L-NAME increased EFS-induced vasoconstriction more markedly in rats supplemented with Prodefen^®. Both neuronal NO release and neuronal NOS activity were enhanced by Prodefen^®, through a hyperactivation of protein kinase (PK)A, PKC and phosphatidylinositol 3 kinase-AKT signaling pathways. The superoxide anion scavenger tempol increased both NO release and DEA-NO vasodilation only in control animals. Prodefen^® caused an increase in both nuclear erythroid related factor 2 and superoxide dismutase activities, consequently reducing both superoxide anion and peroxynitrite releases. In summary, Prodefen^® could be an interesting non-pharmacological approach to ameliorate hypertension.